The present invention relates to a container for storing and handling bulk material. Preferably, the present invention relates to a container for a freight vehicle or other carrier facility.
Classical freight vehicles with hopper bottom are provided with discharge surfaces having angles of repose of approximately 45xc2x0 to facilitate discharge of bulk goods in order to ensure complete unloading by gravity. However, the hopper bottom increases the construction cost of these freight vehicles. Examples of such freight vehicles are shown in U.S. Pat. Nos. 3,756,469 and 4,092,051.
Another proposal for lifting bulk material and creating an adequate angle of repose for optimal gravity discharge concerns collapsible bags that are inflated by blower systems. There is also known in the art, bulk unloading systems that do not require fixed hoppers nor inflatable bags. Such a bulk unloading system may be a collapsible rectangular liner having a collapsible funnel-shaped base wherein after partial discharge, the collapsible liner is manually raised by way of a winch to extend the collapsible funnel-shaped base above the angle of repose of the bulk material and thereby complete discharge of the bulk material. An example of this is shown in U.S. Pat. No. 4,541,765.
While the containers known in the art have resulted to the advancement within the present field, they do not provide a container where the discharging process of the bag is performed efficiently and is practically self-operational.
It is therefore an object of the present invention to provide a container for storing, handling and transporting bulk material that will fulfil the above mentioned needs.
In accordance with the present invention, that object is achieved with a container comprising a flexible bag having a top portion provided with at least one filling inlet for filling the bag. The flexible bag also has a bottom portion provided with a discharging outlet for discharging the bag. The container also comprises a collapsible frame for supporting and containing the bag. The collapsible frame comprises two parallel rigid members slidable with respect to a structure, the two rigid members being located mostly inside the bag for supporting the top portion thereof. Furthermore, the container comprises several resilient means connected to the collapsible frame for upwardly and resiliently biasing side walls of the bag.
The present invention is also directed to a carrier unit for a freight vehicle that comprises at least one container as defined above.
Advantageously, the present invention offers a container that is easy to use and simple to manufacture. Moreover, the container of the present invention eliminates almost any human intervention during the unloading process of the bag, thus the present invention offers a container provided with a self-discharging mechanism.